Tektronix RSA5103A phase signal acquisition

Hello, I'm using N9020A Tektronix RSA5103A Signal Analyzer to get the spectrum of a signal; what I would like to do is to perform an IFFT of the signal. Unfortunaltely the phase information is missing in the data that I acquired. There is another way to acquire magnitude and phase of the spectrum, maybe with an IQ measurement? With the IQ what type of data I'm going to acquire? Then it will be possible to simply do an IFFT with Matlab? Thank you in advance for your help. Cheers, Serena

For the N9020A, you will want to use the IQ Waveform measurement and capture the IQ Data of the signal of interest. You can reference the manual below for the details:

http://cp.literature.agilent.com/litweb/pdf/N9060-90029.pdf

The IQ Data is represents the values of the I (in-phase) and q (quadrature) components of the real signal on the IQ plane in the time domain.

Where I*cos(wt)+jQsin(wt) is represents the time domain signal

And

Sqrt(I^2+Q^2) is the magnitude of the time domain signal

And

Arctan(I/Q) is the phase of the time domain signal

For a particular sample.

Matlab has an complex FFT function that allows complex values as inputs to the FFT function. You will get the complex frequency domain representation of the signal as an output of the function. You can use this with the IFFT function to get the original real signal back in the time domain.